Slate Pencil Natural Lime Stone Chalk Pencil pack of 50 pencils natural chalk pencils cut from natural lime stone, set of 50 pencils 4 to 5 mm thickness approximately non toxic if consumed BUT PLEASE DO NOT RATE AND GIVE NEGATIVE FEEDBACK BASED ON TASTE, IM SELLING THESE CHALK PENCILS FOR PURPOSE OF WRITING ON BLACK BOARD ONLY. safe for children they are soft and brittle hence sure to break during transit